CGL_Module4-ST12-BI1.pdf

General Biology 1 4 “Transport Mechanism” MR. CLEARED LUYA  NO. 4 GENERAL BIOLOGY 1 Transport Mechanism describe the structural components of the cell membrane relate the structure and composition of the cell membrane to...

General Biology 1 4 “Transport Mechanism” MR. CLEARED LUYA  NO. 4 GENERAL BIOLOGY 1 Transport Mechanism describe the structural components of the cell membrane relate the structure and composition of the cell membrane to its function explain transport mechanisms in cells (diffusion, osmosis, facilitated transport, active transport) differentiate exocytosis and endocytosis  NO. 4 GENERAL BIOLOGY 1 In cellular biology, membrane transport refers to the collection of mechanisms that regulate the passage of solutes such as ions and small molecules through biological membranes, which are lipid bilayers that contain proteins embedded in them. NO. 4 GENERAL BIOLOGY 1 NO. 4 GENERAL BIOLOGY Plasma Membrane The plasma membrane, also called the cell membrane, is the membrane found in all cells that separates the interior of the cell from the outside environment.  NO. 4 GENERAL BIOLOGY Fluid Mosaic Model According to the fluid mosaic model, the plasma membrane is a mosaic of components—primarily, phospholipids, cholesterol, and proteins—that move freely and fluidly in the plane of the membrane.  NO. 4 GENERAL BIOLOGY Principal Components of the Plasma Membrane Phospholipid Bilayer: A phospholipid is a lipid made of glycerol, two fatty acid tails, and a phosphate-linked head group. Biological membranes usually involve two layers of phospholipids with their tails pointing inward, an arrangement called a phospholipid bilayer. Cholesterol: another lipid composed of four fused carbon rings, is found alongside phospholipids in the core of the membrane.  NO. 4 GENERAL BIOLOGY Principal Components of the Plasma Membrane Membrane Proteins: may extend partway into the plasma membrane, cross the membrane entirely, or be loosely attached to its inside or outside face. Glycoproteins and Glycolipids: Carbohydrate groups are present only on the outer surface of the plasma membrane and are attached to proteins, forming glycoproteins, or lipids, forming glycolipids. NO. 4 GENERAL BIOLOGY Principal Components of the Plasma Membrane NO. 4 GENERAL BIOLOGY Cell Transport Mechanisms  NO. 4 GENERAL BIOLOGY Cell Transport Mechanisms 2 Types of Transport Mechanism 1.Passive transport: occurs when substances cross the plasma membrane without any input of energy from the cell. No energy is needed because the substances are moving from an area where they have a higher concentration to an area where they have a lower concentration. 2.Active transport: require energy to cross a plasma membrane often because they are moving from an area of lower concentration to an area of higher concentration.  NO. 4 GENERAL BIOLOGY Passive Transport Simple Diffusion: molecules move down their gradients through the membrane. Molecules that practice simple diffusion must be small and nonpolar*, in order to pass through the membrane. Osmosis: a specific type of diffusion; it is the passage of water from a region of high water concentration through a semi-permeable membrane to a region of low water concentration. Water moves in or out of a cell until its concentration is the same on both sides of the plasma membrane NO. 4 GENERAL BIOLOGY Passive Transport  NO. 4 GENERAL BIOLOGY Passive Transport Facilitated Diffusion: diffusion that is helped along (facilitated by) a membrane transport channel. These channels are glycoproteins (proteins with carbohydrates attached) that allow molecules to pass through the membrane. These channels are almost always specific for either a certain molecule or a certain type of molecule (i.e. an ion channel), and so they are tightly linked to certain physiologic functions. NO. 4 GENERAL BIOLOGY Passive Transport  NO. 4 GENERAL BIOLOGY Active Transport Sodium-Potassium Pump: a mechanism of active transport that moves sodium ions out of the cell and potassium ions into the cells. Both ions are moved from areas of lower to higher concentration, so energy is needed for this "uphill" process. The energy is provided by ATP. The sodium-potassium pump also requires carrier proteins. Carrier proteins bind with specific ions or molecules, and in doing so, they change shape. As carrier proteins change shape, they carry the ions or molecules across the membrane. NO. 4 GENERAL BIOLOGY Active Transport  NO. 4 GENERAL BIOLOGY Active Transport Vesicle Transport: Some molecules, such as proteins, are too large to pass through the plasma membrane, regardless of their concentration inside and outside the cell. Very large molecules cross the plasma membrane with a different sort of help.  NO. 4 GENERAL BIOLOGY Vesicular Transport Endocytosis: type of vesicle transport that moves a substance into the cell. The plasma membrane completely engulfs the substance, a vesicle pinches off from the membrane, and the vesicle carries the substance into the cell. When an entire cell or other solid particle is engulfed, the process is called phagocytosis. When fluid is engulfed, the process is called pinocytosis. When the content is taken in specifically with the help of receptors on the plasma membrane, it is called receptor-mediated endocytosis. NO. 4 GENERAL BIOLOGY Vesicular Transport Exocytosis: a type of vesicle transport that moves a substance out of the cell. A vesicle containing the substance moves through the cytoplasm to the cell membrane. Then, the vesicle membrane fuses with the cell membrane, and the substance is released outside the cell. NO. 4 GENERAL BIOLOGY Vesicular Transport  NO. 4 GENERAL BIOLOGY Homeostasis The process of maintaining stable conditions inside a cell (or an entire organism) is homeostasis. Homeostasis requires constant adjustments because conditions are always changing both inside and outside the cell. By moving substances into and out of cells, they keep conditions within normal ranges inside the cells and the organism as a whole. NO. 4 GENERAL BIOLOGY Homeostasis NO. 4 General Biology 1 Q1.4.1-1 TRANSPORT MECHANISMS colored pens, colored papers, glue and strings, paper, pen none  NO. 4 General Biology 1 Q1.4.1-1 IN A CREATIVE WAY, PRESENT IN FRONT OF THE CLASS THE TRANSPORT MECHANISM  NO. 4 Earth and Life Science Q1.1.1-1 For Flexible Distance Learning: Screenshot of hand written answer on bond paper and uploaded at Edmodo Apps For Modular Distance Learning: Handwritten bond paper and submitted at AISAT Campus October 23, 2023 NO. 4 General Biology